NED Abstract

Copyright by European Southern Observatory (ESO).
Reproduced by permission
2008A&A...492...31D
On the frequency, intensity, and duration of starburst episodes
triggered by galaxy interactions and mergers
di Matteo, P.; Bournaud, F.; Martig, M.; Combes, F.; Melchior, A.-L.;
Semelin, B.
Abstract. We investigate the intensity enhancement and the duration of
starburst episodes triggered by major galaxy interactions and mergers.
We analyze two large statistical datasets of numerical simulations.
These have been obtained using two independent and different numerical
techniques to model baryonic and dark matter evolution that are
extensively compared for the first time. One is a Tree-SPH code, the
other one is a grid-based N-body sticky-particles code. We show that, at
low redshift, galaxy interactions and mergers in general trigger only
moderate star formation enhancements. Strong starbursts where the star
formation rate is increased by a factor greater than 5 are rare and
found only in about 15% of major galaxy interactions and mergers.
Merger-driven starbursts are also rather short-lived, with a typical
duration of activity of a few 10^8^ yr. These conclusions are found to
be robust, independent of the numerical techniques and star formation
models. At higher redshifts where galaxies contain more gas, gas
inflow-induced starbursts are neither stronger nor longer than their
local counterparts. In turn, the formation of massive gas clumps,
results of local Jeans instability that can occur spontaneously in
gas-rich disks or be indirectly favored by galaxy interactions, could
play a more important role in determining the duration and intensity of
star formation episodes.
Key words: galaxies: evolution, galaxies: interactions, galaxies:
starburst, methods: numerical